Merriam-Webster's Word of the Day for March 29, 2017 is: Occam's razor \AH-kumz-RAY-zer\ noun : a scientific and philosophic rule that entities should not be multiplied unnecessarily which is interpreted as requiring that the simplest of competing theories be preferred to the more complex or that explanations of unknown phenomena be sought first in terms of known quantities Examples: Invoking Occam's razor, Randall concluded that the sill was wet most likely because someone left the window open during the storm. "To even describe the plot is to make clear how phantasmagorical the whole idea is. Occam's razor applies here. Or, as medical students are taught, when you hear hoofbeats, think horses not zebras." — Paul Cassell, The Washington Post, 6 Feb. 2017 Did you know? [William of Occam](http://www.merriam-webster.com/dictionary/occam) (also spelled "Ockham") didn't invent the rule associated with his name. Others had espoused the "keep it simple" concept before that 14th-century philosopher and theologian embraced it, but no one wielded the principle (also known as the "law of [parsimony](http://www.merriam-webster.com/dictionary/parsimony)") as relentlessly as he did. He used it to counter what he considered the [fuzzy logic](http://www.merriam-webster.com/dictionary/fuzzy%20logic) of his theological contemporaries, and his applications of it inspired 19th-century Scottish philosopher Sir William Hamilton to link Occam with the idea of cutting away extraneous material, giving us the modern name for the principle.